Shungite-derived graphene as a carbon support for bifunctional oxygen electrocatalysts

Abstract

Abstract Metal–air batteries (MABs) and regenerative fuel cells (RFCs) technologies rely on a combination of efficient electrochemical oxygen evolution and oxygen reduction reactions (OER and ORR, respectively). However, such bifunctional oxygen electrocatalysts also rely on the use of readily accessible carbon supports. Herein, we show that shungite, a natural mineral, can serve as an efficient support for development of bifunctional electrocatalysts. Namely, we purify the mineral to remove additional metals and screen various combinations of cobalt, iron and nitrogen sources to identify electrochemically most suitable system to serve as an active bifunctional oxygen electrocatalyst material.